Combines for harvesting various crop materials are well known in the art. A typical combine includes a header assembly for harvesting crop material, a feeder assembly for receiving and rearwardly moving the harvested crop material, and a threshing apparatus for receiving the crop material from the feeder assembly and for separating material such as grain from material other than grain.
The header assembly is connected to and extends across a forward end of a fore-and-aft extending frame of the combine A conventional header assembly includes a reciprocating knife assembly for cutting the crop material, a harvesting apparatus or reel, and a laterally elongated consolidating auger for moving the crop material received from the harvesting apparatus toward a central location.
The feeder assembly receives the crop material advanced or moved toward the central location and feeds it upwardly and rearwardly toward the threshing apparatus. A conventional feeder assembly includes a conveyor comprised of a plurality of laterally spaced fore-and-aft extending endless driving chains and a series of laterally extending feeder slats. The chains of the conveyor are entrained about driving sprockets or drums. The feeder slats are typically secured to the driving chains as with pin connectors at opposite ends of the slats. The feeder assembly further includes a feeder housing which rotatably mounts the drums and substantially envelopes the conveyor. An outer surface on each slat extends above a bottom wall on the housing and coacts therewith in rearwardly advancing crop material toward the threshing apparatus.
The threshing apparatus receives the crop material from the feeder assembly. Different combine manufacturers provide different threshing apparatus designs. An axial-flow threshing apparatus, however, provides a beneficial threshing action by threshing the grain several times repeatedly, but gently, as it spirals around a large diameter rotor assembly.
At its forward crop receiving end, an axial-flow type threshing apparatus typically includes a transition housing with an impeller rotatably mounted therewithin. The feeder system introduces the crop material to the impeller in an undershot manner. Thereafter, the impeller forcibly moves the crop material radially outward and rearward toward the rotor assembly.
As is apparent, the feeder assembly is an important mechanism of the combine and can greatly affect combine efficiency. At its forward end, the conveyor acts to strip the crop material from the auger of the head assembly. To affect an aggressive feeding action, the forward drum of the conveyor is adjusted such that an outer surface or profile of the feeder slats "reaches" in close proximity to the auger of the header assembly.
Although enhancing feeding action, an extended reach offered by the outer profile of the slats decreases swing clearance on opposite sides of the conveyor. At a forward end of the feeder assembly, the slats swing about the periphery of the front drum in close proximity to flights on the auger of the head assembly. Adjusting the front drum to extend the reach of the slats into proximity with the auger of the header assembly likewise extends the driving chains into the crop material flow path, thus hindering the flow of material into the conveyor.
The rear drum of the feeder assembly is likewise adjustable in a fore-and-aft direction. To reduce backfeed to the conveyor, the reach of the feeder slats at the rear end of the conveyor is extended proximate to a front face of the impeller of the rotor assembly.
There is a direct relation between the reach of the feeder slats at the rear end of the conveyor and the introduction of crop material to the impeller of the rotor assembly. Adjusting the feeder slats to reach closely adjacent the front face of the impeller of the rotor assembly normally raises the feed zone wherein crop material is introduced to the rotor assembly.
At opposite sides of the conveyor, crop material is advantageously introduced to the periphery of the impeller. Raising the introductory feed zone or region has minimal effect on crop material introduced toward the impeller periphery. At the center of the conveyor, however, whereat the majority of crop material is concentrated, raising the feed zone causes the crop material to be introduced to the impeller closer to the axis of rotation of the rotor assembly Accordingly, the advantage of introducing crop material toward the high speed impeller periphery is lost. As will be appreciated, introducing crop material closer to the axis of rotor assembly rotation often results in backfeed problems on the feeder system.
In addition to the above, known feeder assemblies are often prone to malfunctions caused by part breakage and deformation. The parts which break or deform most often include the elongated feeder slats and the connectors used to attach the feeder slats to the driving chains.
Breakage of the connectors and deformation of the slats can result from a variety of conditions. As an example, overloading of crops on the conveyor, particularly when accompanied by an excessive wedging or buildup of crop material between the slats and the conveyor housing, will tend to break or deform such parts. Moreover, encountering obstacles such as rocks and stones while the conveyor is moving will cause impact loading and result in deflection of the slats. These and other conditions are not at all uncommon in combine operations.
As will be appreciated, when an obstacle impacts with a feeder slat, the slat deflects and its ends tend to laterally pull away from the connector securing the slat to the respective driving chain. Such impacts can cause permanent deformation of the slats and/or immediate breakage of the connectors which secure the slats to the chains. Time consuming repairs and/or replacement of such slats and connectors adversely affects combine operation often when harvesting time is at a premium. Not repairing such parts often results in vibrations to the combine and may increase the extent of damage to the combine.
Thus, there is a desire and need for a feeder assembly which promotes advancement of crop material between the header assembly and threshing apparatus and which is designed to tolerate the extreme forces and impact loading normally occurring during combine operation.